145
AXPZ20 KNHC 251551
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Sep 25 2024

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1530 UTC.

...SPECIAL FEATURES...

Tropical Storm John is centered near 16.2N 101.4W at 25/1500
UTC, moving east at 2 kt. Estimated minimum central pressure is
1000 mb. Maximum sustained wind speed is 35 kt with gusts to 45
kt. Seas of 12 ft or greater are occurring within 210 NM in the
southern semicircle with peak seas near 14 ft. Multiple areas of
strong convection are occurring around the center, with moderate
to strong convection occurring within 350 NM to the west and
southwest of the center, and within 250 NM to the south and east
of the center. John is forecast to strengthen as it approaches
the coast of southern Mexico on Thursday. John will move to
16.3N 101.2W this evening, 16.7N 101.1W Thu morning, 17.3N 101.1W
Thu evening, weaken to a tropical depression near 17.8N 101.2W
Fri morning, and dissipate Fri evening. Through Friday, Tropical
Storm John is expected to produce additional rainfall amounts of
10 to 20 inches with isolated totals around 30 inches across the
Mexican States of Guerrero, Oaxaca, coastal Chiapas, and coastal
Michoacan. Swells associated with John are forecast to continue
to affect the coast of southern Mexico through the week, with the
potential for dangerous surf and rip currents. Please read the
latest HIGH SEAS FORECAST issued by the National Hurricane Center
at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and
the latest John NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

A Central American Gyre will continue to produce periods of
excessive rainfall over southern Mexico and Central America for
the remainder of the week, as well as the adjacent western
Caribbean and eastern Pacific waters between 80W and 95W. This
scenario, combined with daytime heating and orographic lifting,
could produce dangerous flash flooding and mudslides across the
area. Furthermore, strong to near gale force winds, rough seas
and heavy thunderstorms are forecast to affect the offshore
waters between Costa Rica and Guatemala through the end of the
week. Please follow the forecasts from your local weather offices
for more detailed information.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough axis extends from 14N109W to beyond 11N140W.
Aside from the convection related to Tropical Storm John and the
Central American Gyre, scattered moderate to locally strong
convection is occurring from 08N to 11N between 132W and 140W.
Scattered moderate convection is occurring from 11N to 14N
between 110W and 121W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please refer to the Special Features section above for
information on Tropical Storm John and on the Central American
Gyre (CAG).

A 1003mb low pressure is centered near 34N112W and troughing
extends through the Gulf of California toward Tropical Storm
John. This pattern supports moderate to fresh NW winds and seas
of 4-6 ft across much of the Mexico offshore waters. Light to
gentle breezes and seas of 1-3 ft prevail in the Gulf of
California. Farther south, south of 18N and east of 105W, strong
to near gale force winds are occurring along the periphery of
Tropical Storm John, and associated seas are 9-14 ft.

For the forecast away from the direct impacts from Tropical Storm
John, strong to near gale force winds will continue south of 18N
and east of 106W through late Thu. Winds will slowly diminish
below strong speeds through Fri, diminishing further on Sat.
Rough to very rough seas will accompany these winds through late
Fri before slowly subsiding Sat into Sun. Elsewhere, mostly
fresh northwest winds and moderate seas will occur across the
remainder of the Mexican offshore waters through Sat, with the
exception of the Gulf of California, where winds will remain
light to gentle.

...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...

Please refer to the Special Features section above for
information on the Central American Gyre (CAG).

Moderate to fresh SW winds are occurring over the coastal waters
from Guatemala through Nicaragua, and seas of 6-9 ft are noted in
this area. Gentle to moderate S to SW winds and seas of 4-7 ft
prevail elsewhere. Scattered moderate to locally strong
convection is noted from 09N to 14N east of 94W, with similar
convection noted offshore of Panama and Colombia. Strong winds
and rough seas will occur near convection.

For the forecast, moderate to fresh SW winds will continue across
the offshore waters from Nicaragua northwestward through early
Thu, with moderate winds prevailing into the weekend. Moderate to
rough seas will accompany these winds, with seas slowly
subsiding north of Costa Rica by the end of the week. Elsewhere,
gentle to moderate SW winds will continue over the forecast
waters through the forecast period. Scattered to numerous showers
and thunderstorms will continue over most of the offshore waters
through the rest of the week.

...REMAINDER OF THE AREA...

Strong to near gale force winds prevail over the waters on the
periphery of Tropical Storm John, generally north of 09N and
east of 109W. Seas of 9 to 12 ft are likely occurring in this
region. Moderate to locally fresh winds are noted south of the
monsoon trough east of 125W and north of 08N. Elsewhere, gentle
to moderate N to NE winds prevail north of the monsoon trough
with seas of 4-6 ft.

For the forecast, strong to near gale force winds will continue
north of 09N and east of 114W through Fri before winds slowly
diminish through Sat. Rough to locally very rough seas will
accompany these winds, with seas slowly subsiding this weekend
into early next week. Otherwise, little change is expected from
the current conditions through early next week.

$$
ADAMS